Lower Warner-Bratzler Shear Force Research Articles

Chemical and fatty acid composition, collagen, calpain and troponin T contents and quality characteristics of five muscle types in native Thai cattle

In this study, chemical composition, fatty acids, collagen solubility, calpains, and troponin T degradation were investigated in various muscles of native Thai cattle (NTC). Five muscles, namely Bicep femoris, Infraspinatus, Longissimus thoracis, Supraspinatus and Semimembranosus were sampled from five Kho Isaan bulls. Moisture content of Longissimus thoracis was lower (p < 0.05) than others. Protein content of Longissimus thoracis, Bicep femoris and Semimembranosus was higher (p < 0.05) than that of Infraspinatus and Supraspinatus. Infraspinatus and Longissimus thoracis had higher fat content (p < 0.05) than Bicep femoris and Semimembranosus. Muscle pH, color, and drip loss did not differ between muscles. Semimembranosus and Supraspinatus showed higher cook loss (p < 0.05) than Infraspinatus and Longissimus thoracis. Infraspinatus had the lowest Warner–Bratzler shear force (p < 0.05). Supraspinatus, Infraspinatus and Bicep femoris had higher (p < 0.05) soluble, insoluble and total collagen content than Semimembranosus and Longissimus thoracis. Infraspinatus had higher collagen solubility than Semimembranosus and Supraspinatus. Collagen content and solubility were not affected by ageing time. The relative band intensities of intact troponin T and its degradation product at 2- and 14-days postmortem were higher in Longissimus thoracis than in other muscles. Infraspinatus and Supraspinatus had significantly higher expression of m-calpain and calpastatin genes than Longissimus thoracis, Bicep femoris, and Semimembranosus. Total fatty acid was higher while the percentage of C22:6n-3 was lower in Infraspinatus and Longissimus thoracis (p < 0.05) than in other muscles. These results show differences in specific nutritional, technological and eating quality characteristics of NTC muscles and thus provide information for optimizing storage and processing conditions for various NTC muscles.

Genetic lines influenced the texture, collagen and intramuscular fat of pork longissimus and semimembranosus

The effects of genetic lines (PM-LR – Pure maternal, Landrace-type; PM-LW – Pure maternal, Large White-type; PM-D – Pure maternal, Duroc-type; SynT-LWLR – Synthetic terminal, Large white and Landrace-type; PT-D – Pure terminal, Duroc-type; and PT-LW – Pure terminal, Large White-type) on carcass traits and pork quality, including cooking loss, Warner-Bratzler shear force (WBSF), texture profile analysis (TPA), collagen content and solubility and intramuscular fat (IMF) content of Longissimus thoracis et lumborum (LTL) and Semimembranosus (SM), were investigated. The results showed that all terminal lines had lower backfat thickness than maternal lines, but muscles from line SynT-LWLR had the highest hardness and cohesiveness and the lowest IMF content. The SM showed higher hardness, adhesiveness, springiness, chewiness, collagen, and IMF content but lower WBSF and collagen solubility than LTL. Collagen and IMF content affected WBSF and TPA parameters across both muscles and in LTL alone. Significant relationships between collagen content and texture parameters were found in line PT-D. Genetic lines and muscles affect the contribution of collagen and IMF to pork texture.

Effects of different protein phosphorylation levels on the tenderness of different ultimate pH beef

This study investigated the relationship between tenderness and protein phosphorylation levels of normal ultimate pH (pHu, 5.4–5.8, NpHu), intermediate pHu (5.8–6.2, IpHu) and high pHu (≥6.2, HpHu) Longissimus lumborum from beef. During 21 d of ageing, the HpHu group had the lowest Warner-Bratzler shear force (WBSF) values, while the IpHu group showed the highest and even after 21 days of ageing still had high levels. In the late stage of the 24 h post-mortem period the faster degradation rate of troponin T and earlier activation of caspase 9 in the HpHu group were the key reasons for the lower WBSF compared with the NpHu and IpHu groups. The activity of caspase 3 cannot explain the tenderness differences between IpHu and HpHu groups, since their activities did not show any difference. At 24 h post-mortem, 17 common differential phosphorylated peptides were detected among pHu groups, of which nine were associated with pHu and WBSF. The higher phosphorylation level of glycogen synthase may have caused the delay of meat tenderization in the IpHu group.

Changes in physical architecture and lipids compounds in skeletal muscle from Pekin duck and Liancheng white duck

As a complex food, meat displays various biochemical properties that are determined to a great extent by physical architecture and lipid metabolites. Pekin duck and Liancheng white duck are elite breeds with distinct characteristics. Here, we explored the development of the muscle fibers from embryonic stage to 10-wk after birth, and muscle fibers grow slowly after 8-wk. We investigated the meat quality, ultrastructure, lipidomics profiling, and lipids spatial distribution of skeletal muscle at 8 wk. Pekin duck has lower Warner-Bratzler shear force (WBSF) (P < 0.05), high intramuscular fat (IMF) (P < 0.01), longer and wider sarcomere, and higher mitochondrial density (P < 0.001). Liancheng white duck with tighter collagen architecture. A total of 950 lipids from 6 lipid classes identified with lipidomics were analyzed, the levels of GP, GL, and PR were significantly higher in Pekin duck (P < 0.05), SL and ST were significantly higher in Liancheng white duck (P < 0.05). There were 333 significantly different lipids (|log2(Fold Change)| ≥ 1 and FDR < 0.05) screened, most lipids distributed in the muscle tissue were uniform, but some specifically distributed in connective tissue. To some extent, the results demonstrate the high lipid deposition capacity of Pekin duck and the high medicinal function of Liancheng white duck. Our study provides new insights into the relationship between skeletal muscle architecture and meat toughness, which increased the knowledge of lipidomic characteristics and provide a basis for duck meat authentication.

29 Impact of Extended Feeding Duration on Trained Panel Analysis of Locally Grown Beef

Abstract The objective of this study was to evaluate the impact of increased finishing weights on trained panel analysis and Warner-Bratzler shear force (WBSF) values of locally grown beef. Angus crossbred steers (n = 48) at an average weight of 340.9 kg were divided among two treatments: short-fed (SF) = 522.7 kg average final weight and long-fed (LF) = 613.6 kg average final weight to simulate a beef direct marketing operation. Cattle were split into two pens (n = 12 calves/treatment in each pen) and each pen had access to four automated feeders, which were filled as needed for ad libitum intake. Body weights were recorded at 28 d intervals throughout the finishing process to determine harvest dates and measure cattle performance. Finished steers were transported to a commercial processing facility. A strip loin was collected from the right side of each carcass approximately 48 hours following harvest. Strip loins were wet aged in the absence of light for 21 d, then cut into 2.54 cm steaks and frozen at -20° C until analysis. Sensory evaluations and WBSF were conducted as outlined by the AMSA Sensory Guidelines to evaluate the traits of juiciness, beef flavor intensity, off-flavor intensity, connective tissue amount, myofibrillar tenderness and overall tenderness. Data were analyzed as a completely randomized design with the fixed effect of final cattle weight and the random effect of panel session. Peak internal temperature was included in the model as a covariate. Statistical differences were determined with α ≤ 0.05 and tendencies were observed between 0.06 to 0.09. No differences were observed between treatment groups for initial or sustained juiciness, myofibrillar tenderness, connective tissue amount or overall tenderness (P ≥ 0.140). Steaks from LF cattle produced lower WBSF scores (P &amp;lt; 0.05) compared with SF cattle. Additionally, steaks from LF cattle produced less off flavors (P = 0.05) than SF cattle. Long fed cattle steaks tended to have a greater beef intensity score (P = 0.08). These results indicate that while LF cattle produce more tender beef with more intense beef flavor and less off-flavors, SF cattle still provide a quality eating experience, with less feed input costs. However, if there are potential processing bottlenecks from reduced processing capacity, long fed cattle will also provide a high-quality eating experience as well.

Effect of Novel High-Intensity Ultrasound Technique on Physio-Chemical, Sensory Attributes, and Microstructure of Bovine Semitendinosus Muscle.

The present study aimed to evaluate the effects of high-intensity ultrasound (HIU) application on meat quality traits, sensory parameters, and the microstructure of semitendinosus muscle from Hanwoo cattle. The samples were treated in an ultrasonic bath (35 kHz) at an intensity of 800 W/cm2 for 60 min, followed by aging at 1°C for 0, 3, and 7 days. The application of ultrasound resulted in lower Warner-Bratzler shear force and higher myofibrillar fragmentation index values during the storage period. HIU also enhanced the tenderness, flavor, umami, and overall acceptability of cooked beef muscle. However, the electronic tongue evaluation results showed higher umami values in the control treatment on the seventh day of storage. The microstructure of sonicated meat showed disorganized myofibrillar architecture and swelling in the A-band region of sarcomeres during the storage period, which led to greater meat tenderness. The heatmap illustrated the high abundance of α-linolenic acid (C20:5n3) and eicosapentaenoic acid (C18:3n3) in sonicated meat samples on the third day of the storage. These results showed that HIU is a potential method for tenderizing and improving the sensory attributes of beef without compromising other quality aspects.

Effects of Aging Methods and Periods on Quality Characteristics of Beef.

The objective of this study was to determine effects of aging methods (wet-aged, dry-aged, and packaged dry-aged) during 60 d on quality traits and microbial characteristics of beef. Wet-aged beef was packed by vacuum packaging and stored in a 4°C refrigerator. Dry-aged beef was used without packaging. Packaged dry-aged beef was packaged in commercial bags. Dry-aged and packaged dry-aged samples were stored in a meat ager at 2°C-4°C with 85%-90% relative humidity. Meat color, crust thickness, aging loss, cooking loss, Warner-Bratzler shear force (WBSF), texture profile analysis, Torrymeter, meat pH, water activity, volatile basic nitrogen (VBN), thiobarbituric acid reactant substances (TBARS), and microbial analysis were measured or performed every 15 d until 60 d of aging time. Meat color changed significantly with increasing aging time. Differences in meat color among aging methods were observed. Aging losses of dry-aged and packaged dry-aged samples were higher than those of wet-aged samples. Wet-aged beef showed higher cooking loss, but lower WBSF than dry-aged and packaged dry-aged beef. VBN and TBARS showed an increasing tendency with increasing aging time. Differences of VBN and TBARS among aging methods were found. Regarding microbial analysis, counts of yeasts and molds were different among aging methods at the initial aging time. Packaged dry-aged and dry-aged beef showed similar values or tendency. Significant changes occurred during aging in all aging methods. Packaged dry aging and dry aging could result in similar quality traits and microbial characteristics of beef.

Early postmortem muscle proteome and metabolome of beef longissimus thoracis muscle classified by pH at 6 hours postmortem

The objective was to identify metabolome and proteome differences at 1 h and 1 d postmortem between longissimus thoracis (LT) muscle classified based on 6 h pH values. Twenty beef LT rib sections were sorted based on 6 h postmortem pH values into low (LpH; pH < 5.55; n = 9) and high (HpH; pH > 5.84; n = 8) pH classifications. Warner-Bratzler shear force (WBSF), desmin degradation, and calpain-1 autolysis were measured. Two-dimensional difference in gel electrophoresis (3–10, 4–7, and 6–9 pH range) and Tandem mass tagging (TMT) protein analyses were employed to determine how the sarcoplasmic protein profile varied across pH classification. Non-targeted metabolomic analyses were conducted on extracts prepared at 1 h and 1 d postmortem. The LpH classification had a lower WBSF value at 1 d postmortem, which was explained by greater calpain-1 autolysis and desmin degradation at 1 d postmortem. Proteome and metabolome analysis revealed a phenotype that promotes more rapid energy metabolism in the LpH group. Proteome and metabolome analyses identified energy production, apoptotic, calcium homeostasis, and proteasome systems influencing pH classifications that could explain the observed pH, proteolysis, and beef tenderness differences. SignificanceThis study is the first to identify proteomic and metabolomic variations early (1 h and 1 day) postmortem that are linked to differences in early (6 h) postmortem pH values and to tenderness differences at 1 day postmortem. This study integrates postmortem biochemical features (protein degradation, proteome, and metabolome variations) to postmortem pH decline and eating quality of beef steaks. Potential biomarkers of more rapid postmortem metabolism linked to earlier tenderization in beef are suggested. Identification of these biochemical features will assist in predicting the eating quality of beef products.

Effect of Packaging Type and Aging on the Meat Quality Characteristics of Water Buffalo Bulls

Simple SummaryThe water buffalo is found worldwide, but mainly in Asian countries, i.e., India, Pakistan, and China. Buffalo meat can be a viable option to fulfill the future protein demands of the world’s population. Presently, very little information is available regarding buffalo meat quality attributes under different packaging types. Therefore, this study was designed to evaluate the effect of packaging type and aging time on the meat quality characteristics (instrumental color, WBSF, cooking loss, thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVB-N) of longissimus lumborum steaks. The results showed that vacuum packaging and aging were the most effective in decreasing the WBSF values of buffalo meat.The present study determined the effect of the packaging type and aging time on the meat quality of water buffalo (Bubalus bubalis) bulls. A total of n = 36 longissimus lumborum (LL) muscles from n = 18 buffalo bulls were obtained. Half LL muscles were packed in modified atmosphere packaging (Hi-O2 MAP), vacuum packaging (VP), and oxygen-permeable packaging (OP) on day 1, while the other half were aged for 7 days. Meat instrumental color, cooking loss, Warner–Bratzler shear force (WBSF), thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVB-N) of the LL steaks were analyzed, both on unaged and aged buffalo meat. Color CIE L* and C* values on all display days and a* on the first 4 days of the simulated retail display under Hi-O2 MAP packaging were significantly higher than those of the VP and OP. WBSF and TBARS values were also higher under Hi-O2 MAP as compared to the other packaging. Steaks under OP exhibited lower cooking loss but higher TVB-N values than the MAP and VP. The 7-day-aged buffalo meat indicated higher instrumental color (L*, a* and C*), cooking loss, and lower WBSF values than fresh meat. This study concluded that Hi-O2 MAP improved the color; however, it negatively influenced the buffalo meat’s WBSF and TBAR values. Furthermore, VP and aging were the most effective in decreasing the WBSF values of buffalo meat.

Effect of Postmortem Phases on Lamb Meat Quality: A Physicochemical, Microstructural and Water Mobility Approach.

To investigate the effect of postmortem phases on lamb meat quality, the physicochemical quality, microstructure and water mobility of oyster cut, short loin, knuckle and silverside muscles from Small-Tail Han sheep were evaluated in the pre-rigor, rigor mortis and post-rigor phases. Pre-rigor lamb meat had higher pH and water holding capacity (WHC), whereas lower CIE L*, b*, hue angle values than rigor mortis and post-rigor meat (p<0.05). The Warner-Bratzler shear force (WBSF) values were higher in rigor mortis short loin and silverside than their pre-rigor and post-rigor counterparts, pre-rigor short loin had lower WBSF value than its post-rigor counterpart (p<0.05). Muscle fibers shrank laterally and longitudinally during the onset of rigor mortis. Rigor mortis and post-rigor lamb meat exhibited wide I-bands, dark A-bands, short sarcomeres and large inter-myofibrillar spaces. The shift of immobilized water to free water and repulsion from the intra-myofibrillar space to the extracellular space result in the increase of water loss in rigor mortis and post-rigor lamb meat. The results of the principal component analysis (PCA) indicated that rigor mortis and post-rigor lamb meat had similar quality properties but different from pre-rigor lamb meat. In conclusion, the lamb meat in the pre-rigor phase had good tenderness, color and WHC. The results of this research could provide some theoretical references for lamb meat production and processing.

Physicochemical and Sensory Assessments in Spain and United States of PGI-Certified Ternera de Navarra vs. Certified Angus Beef.

The physicochemical and sensory differences between the PGI-Certified Ternera de Navarra (CTNA) (Spanish origin) and Certified Angus Beef (CAB) (US origin) were assessed in Spain and the USA. To characterize the carcasses, the ribeye areas (REAs), and marbling levels were assessed in both testing places. Twenty striploins per certified beef program were used as study samples. For sensory analysis, the striploins were vacuum packaged and aged for 7 days at 4 °C and 85% RH in each corresponding laboratory. Thereafter, the samples were half cut and frozen. One of the halves was shipped to the other counterpart-testing place. The fat and moisture percentage content, Warner Bratzler Shear Force (WBSF), and total and soluble collagen were tested for all the samples. The CAB carcasses had smaller REAs (p < 0.0001) and exhibited higher marbling levels (p < 0.0001). The CAB striploins had a higher fat content (p < 0.0001) and required lower WBSF (p < 0.05) than the CTNA samples. Trained panelists rated the CAB samples as juicer (p < 0.001), more tender/less tough (p < 0.0001), and more flavorful (p < 0.0001) than the CTNA counterparts. This study shows that beef from both countries had medium-high tenderness, juiciness, and beef flavor scores and very low off-flavor scores. Relevant differences found between the ratings assigned by the Spanish and the US panelists suggest training differences, or difficulties encountered in using the appropriate terminology for defining each sensory attribute. Furthermore, the lack of product knowledge (i.e., consumption habits) may have been another reason for such differences, despite the blind sensory evaluation.

Muscle fiber characteristics and postmortem quality of longissimus thoracis, psoas major and semitendinosus from Chinese Simmental bulls.

Using Chinese Simmental cattle semitendinosus, psoas major, and longissimus thoracis samples, we assessed muscle fiber characteristics and postmortem quality. The type I, IIA, and IIB fiber diameters were greater in semitendinosus and longissimus thoracis relative to psoas major, with psoas major, semitendinosus, and longissimus thoracis having the highest respective percentages of type I, IIB, and IIA fibers. Psoas major had the highest R 248 and R 250 values and lowest R 258 values at 1‐ and 6‐hr postmortem. Psoas major had the lowest Warner–Bratzler shear force (WBSF), hardness, and chewiness values. The trends of WBSF, hardness, and chewiness changes decreased with increasing aging time. Semitendinosus had higher changes in WBSF than psoas major, and the number % type I fibers was correlated negatively with % changes of WBSF. Therefore, muscles with a high proportion of type IIB fibers and a low proportion of type I had lower tenderness and higher tenderization rate. Further research should be done to seek the optimal composition of muscle fiber type in order to improve beef quality, as muscle fiber type has opposite effect of tenderness background and tenderization rate.

The relationship between myofiber characteristics and meat quality of Chinese Qinchuan and Luxi cattle.

ObjectiveThe objectives of this study were to explore the expression patterns of myosin heavy chain (MyHC) genes of different skeletal muscles from Chinese cattle, and to investigate the relationship between myofiber characteristics and meat quality of M. longissimus lumborum (LL), M. psoas major (PM), and M. semimembranosus (SM) from Chinese Luxi and Qinchuan cattle.MethodsThree major muscles including LL, PM, and SM from Chinese Luxi cattle and Chinese Qinchuan cattle were used in this study. The myofiber characteristics were measured by histochemical analysis. The MyHC isoforms expression was evaluated by real-time quantitative polymerase chain reaction. Quality traits including pH value, meat color, cooking loss, Warner-Bratzler shear force (WBSF) and sarcomere length were determined at day 5 postmortem.ResultsPM muscle had higher pH value, a* value, sarcomere length and lower WBSF value compared to LL and SM muscles (p<0.05). Numbers of type I myofiber and the relative expression of MyHC I mRNA in PM muscle were higher than those of LL and SM muscles (p<0.05). Myofiber diameter of PM muscle was lower than that of LL and SM muscles, regardless of myofiber types (p<0.05).ConclusionAccording to the stepwise linear regression analyses, tenderness was influenced by myofiber characteristics in all three examined muscles. Tenderness of beef muscles from Qinchuan and Luxi cattle could be improved by increasing numbers of type I myofiber.

Associations of Heat-Shock Protein Expression with Meat Quality and Sensory Quality Characteristics in Highly Marbled Longissimus Thoracis Muscle from Hanwoo Steers Categorized by Warner-Bratzler Shear Force Value.

The influence of heat-shock protein (HSP) concentrations at 45 min and 24 h postmortem on meat quality and sensory quality characteristics of longissimus thoracis muscle from highly marbled Hanwoo steers (beef marbling standard grade 6–8) was investigated. Muscle samples were segregated into three groups based on Warner–Bratzler shear force (WBSF) value. The low group exhibited a lower WBSF value compared to the medium and high groups (37.8 vs. 48.9 and 64.3 N, p < 0.001). Muscle pH at 45 min and 24 h postmortem was not different (p > 0.05), and all groups exhibited low ultimate pH value (pH < 5.8). Beef steaks from the low group were significantly easier to pierce and chew, and they left less perceptible residue than the high group (p < 0.05). These differences in tenderness attributes were associated with differences in small HSPs at 45 min postmortem, with the low group exhibiting a lower level of αβ-crystallin and higher levels of HSP20 and HSP27 compared with the high group (p < 0.05). No differences were observed for small HSPs, HSP70, and HSP90 at 24 h postmortem (p > 0.05). Therefore, the expression levels of small HSPs at 45 min postmortem seems to have the potential to be an indicator of tenderness in highly marbled Hanwoo beef with low ultimate pH.

Influence of sous vide and steam cooking on mineral contents, fatty acid composition and tenderness of semimembranosus muscle from Holstein-Friesian bulls

The effects of thermal processing method (sous vide and steam cooking) on Ca, Cu, Fe, Zn, Mg, Mn, K, Na contents, fatty acid composition, Warner-Bratzler shear force (WBSF) and eating quality in beef semimembranosus muscle from Holstein-Friesian bulls were evaluated in the study. Thermal processed meat was characterized by a higher content of Ca, Cu, and Zn and lower content of Na and K than raw meat. Steam-cooked beef showed higher retention values of Cu, Fe and Zn and lower for K and Na compared with sous vide samples. Steam-cooked beef was a good source of Fe and Zn and 100 g of the meat satisfied 118% for Zn recommendations for children. Steam cooking increased the proportion of C18:2, C18:3, C20:1, C20:4 and decreased the proportion of the sum of saturated fatty acids. Sous vide beef had a lower proportion of polyunsaturated fatty acids, including n-3, than steam-cooked beef, but a similar n-6/n-3 ratio. However, sous vide treatment caused lower cooking losses and produced meat products with lower WBSF values and better eating quality than steam cooking.

Bioactivities of wine components on marinated beef during aging

Abstract The objective of this study was to identify particular wine components as responsible for the bioactivities observed in marinated bovine muscle Longissimus lumborum during 7 days of refrigerated storage at 4 °C. Depending on the grape variety, four marinades were considered (300 mL dealcoholized wine/kg meat): Carbernet (CAB), Tempranillo (TEM) and Isabel (ISA), including a control group of samples. CAB and TEM, rich in procyanidins, were more effective against lipid oxidation while ISA, rich in hydroxycinnamic acids, protected proteins against oxidation more efficiently. The lower Warner Bratzler shear force values in beef stakes marinated with ISA could be explained by the inhibition of protein cross-linking. Caftaric acid, the most abundant hydroxycinnamic acid in ISA, was tentatively identified as responsible for this relevant bioactivity. The particular phenolic composition of ISA wine and its high content in organic acids, may explain its effects against Enterobacteriaceae while sugars may have promoted the growth of lactic-acid bacteria in beef marinated with CAB and TEM.

Feeding distillers grains to cattle may affect beef tenderness early postmortem.

The objective of this study was to evaluate the effects of dietary fat source with modified distillers grains plus solubles (MDGS) on beef tenderness through examination of sarcoplasmic reticulum (SR) membrane fatty acid composition, changes in sarcoplasmic calcium concentration, Warner-Bratzler shear force (WBSF), sarcomere length, and proteolysis early postmortem. Steers (n = 256) were fed for 134 d on either corn, or a diet containing 40% full-fat MDGS, 40% de-oiled MDGS, or 38% de-oiled MDGS plus 2% corn oil. Twenty-four USDA Choice carcasses (three carcasses per pen; eight pens per treatment) were selected within each dietary treatment, and strip loins were collected and aged for 2, 9, 16, or 23 d postmortem and subject to retail display (RD) for an additional 7 d. Feeding MDGS increased (P < 0.05) concentrations of linoleic acid (18:2) and tended to increase (P = 0.06) total polyunsaturated fatty acids (PUFA) in the SR membrane. Steaks from cattle fed MDGS had greater sarcoplasmic calcium concentration than steaks from cattle fed corn at day 2 postmortem (P = 0.05). Steaks from steers fed de-oiled MDGS and de-oiled MDGS plus corn oil tended to have lower WBSF values (P = 0.08) than steaks from cattle fed corn at 2 d of aging with 0 d of RD. There were no differences among dietary treatments for sarcomere length (P = 0.92) and troponin-T degradation at 2 d postmortem (P = 0.60). Results suggest that feeding MDGS may increase early postmortem release of calcium into the sarcoplasm due to increased 18:2 and PUFA concentration in the SR membrane, which could result in increased beef tenderness early postmortem.

Comparison of Marbling Fleck Characteristics and Objective Tenderness Parameters with Different Marbling Coarseness within Longissimus thoracis Muscle of High-marbled Hanwoo Steer.

It is important to understand how marbling traits and tenderness differ among beef steaks from the carcass grading site and other regions within the longissimus thoracis (LT) muscle, as these characteristics are closely associated with consumer acceptability and willingness to purchase. Thus, the aim of this study was to compare the marbling fleck traits and objective tenderness parameters in the groups classified by the coarseness index (CI) of marbling fleck (high and low groups) at the carcass grading site (13th thoracic vertebra; 13T) and three different locations (13T, 9T, and 6T) within the LT muscle from well-marbled (marbling score 7 to 9) Hanwoo steer. Image analysis showed that the longitudinal locations had a significant effect on marbling fleck traits. The total area of large marbling fleck divided by the total marbling area (coarseness) was higher at the central region (13T to 12T) compared to the front thoracic region (6T to 5T) in the high CI group (0.23 vs. 0.17, p<0.05), whereas no significant differences were observed in the total number of marbling fleck within the LT muscle in the high or low CI groups (p>0.05). Location effect on objective tenderness parameters within the LT muscle was somewhat limited, although the high CI group had a lower Warner-Bratzler shear force (WBS) value than did the low group (p<0.05). Taken together, the degree of coarseness of marbling fleck decreased from the carcass grading site to the front thoracic site, whereas the objective tenderness parameters, including WBS and hardness, of the grading site did not differ from the other regions within the LT muscle.

Effect of dietary grape pomace on growth performance, meat quality and antioxidant activity in ram lambs

Wine grape pomace (WGP) provides a rich source of polyphenols that can act as powerful antioxidants, but their potential as feed ingredients in the lamb industry remains unexploited. The objective of this study was to investigate the effect of dietary WGP supplementation on growth performance, meat quality and antioxidative activity in the longissimus dorsi (LD) muscle of lambs. A total of eighteen lambs (25.0 ± 0.2 kg of body weight, BW) were randomly selected and equally divided into three groups, and offered diet containing different levels of WGP (0%, 5% and 10%). The results showed that supplementation with 10% dietary WGP increased body weight, average daily gain, and reduced the feed to gain ratio (P < 0.05). There was no observed effect of dietary WGP supplementation on pH, color, cooking loss, or intramuscular fat (IMF). Lambs fed with a WGP-containing diet had lower Warner–Bratzler shear force (WBSF) (P < 0.05), and a decreased collagen content (P < 0.05). The total antioxidative capacity (T-AOC), glutathione peroxidase 4 (GPx4) and superoxide dismutase (SOD) activity were increased when lambs were fed the WGP-containing diet (P < 0.05), whereas no difference in catalase activity was detected. In addition, WGP supplementation decreased ROS and MDA levels induced in animals raised in penned conditions (P < 0.05). Taken together, these results suggest that WGP can be used as a feed ingredient in lamb production to relieve oxidative stress, and improve feed efficiency and meat tenderness, possibly due to the enhanced antioxidative capacity.

Meat Tenderness Characteristics of Ten Major Muscles from Hanwoo Steers according to Quality Grades of Carcasses.

The objective of this study was to determine the influence of quality grade (QG) on meat tenderness characteristics of ten major muscles from Hanwoo steers. A total of 25 Hanwoo carcasses (5 carcasses × 5 QGs) were selected. Intramuscular fat content, collagen content, sarcomere length, and Warner-Bratzler shear force (WBSF) of Longissimus thoracis (LT), Longissimus lumborum (LL), Psoas major (PM), Semisponals (SS), Triceps brachii (TB), Semimembranosus (SM), Gluteus medius (GM), Rectus Abdominis (RA), Superficialis flexor (SF), and Internal and external intercostal (IC) were determined. IC had the highest fat content, followed by LT, RA, LL, PM, GM, SS, SF, TB, and SM. High-fat muscles such as LT, LL, IC, RA, and PM had significantly (p<0.05) different fat contents among QGs. Collagen contents were significantly (p<0.05) different among QGs. With decreasing QG, increasing collagen content was found in muscles. There were significant (p<0.05) differences in sarcomere length among QGs of several muscles. However, no significant (p>0.05) difference in sarcomere length was found among QGs for LL, PM, or RA muscle. PM had the lowest WBSF, followed by LL, LT, RA, IC, GM, SM, SF, SS, and TB. WBSF of QG 1++ was lower than that of QG 1 for SS, TB, and SM. All muscles of QG 1 showed lower WBSF than QG 3 except TB or IC. Results of this study suggested that differences in WBSF among these 10 muscles by QG were due to differences in collagen content and sarcomere length.